Means for controlling the supply of electric currents.



No. 836,279. PATENTED NOV. 20, 1906. F. w. SCHNEIDER.

MEANS FOR CONTROLLING THE SUPPLY OF ELECTRIC OURRENTS. APPLIOATIdON FILED I EO.17, 1903.

v UNITED STATES PATENT OFFICE.

FRIEDRICH WILHELM SCHNEIDER, OF FRANKFORT-ON-THE-MAIN- BOGKENHEIM, GERMANY, ASSIGNOR TO THE FIRM OF VOIGT AND HAEFFNER' AKTIENGESELLSCHAFT, OF FRANKFORTON-. THE-MAIN-BOOKENHEIM, GERMANY.

MEANS FOR CONTROLLING THE SUPPLY OF ELECTRIC CURRENTS.

Specification of Letters Patent.

Patented Nov. 20, 1906.

Application filed December 17, 1903. Serial No. 185,537.

-trolling the Supply of Electric Current, of

which the following is a specification.

This invention relates to improvements in means for controlling the supply of electric current.

It is in many cases necessary to supply electrical power to consumers for a fixed annual' payment, more particularly if there are a large number of consumers, each of whom only uses a small number of lamps or the like. The rate of payment is of course in these cases based on the average consumption and depends on the candle-power of the lamp or the power of the motors used by the consumer. It is, however, possible for the consumer to substitute for the apparatus on which the rate is based apparatus which takes a larger amount of current. This may be done intentionally or unintentionally; but in either case heavy loss to the supplier may be involved which -may extend over a long eriod. The action of fuses is not suiiicient y accurate or reliable for the purpose. Under these circumstances many suppliers of electrical power have been compelled to discontinue supplying current for fixed annual payments, and since electricity-meters are too expensive to be supplied to small customers the custom of the latter must frequently be dispensed with, although it is important.

The object of the present invention'is to provide eflicient means for controlling the supply of currentthat is to say, for preventing the supply of a larger current than that agreed upon. The apparatus for this purpose comprises two interrupters or cutouts formed by makeand-break contacts arranged in the circuit to be controlled and adapted to break the latter temporarily if the current exceeds a certain limit. For this purpose the first interrupter is provided with a device by means of which it is operated when the current exceeds the said limit,

whereupon the current flows through apparatus connected in parallel to the first interrupter and adapted to operate the second interrupter, so that the latter is also operated and the circuit is temporarily broken, this action being repeated as long as the current exceeds the normal value. If, for instance, a sixteen-candle-power lamp is placed in the circuit where only a ten-candle -power lamp ought to be used, the circuit will be alternately broken and closed, so that the lamp will become alternately bright and dark. This Will continue until a lamp of the proper candle-power is substituted for the one which takes too much current. The apparatus can also be used. with advantage in circuits of consumers who have a number of lamps of which only a certain proportion must be used at one time. The apparatus, which can be used .in connection with a time-piece, if desired, can be adjusted to act on a current 'difierence equivalent to two candle-poWeI',

and can be adjusted for various maximum current values.

In the annexed drawings, Figures 1 2, and 3 are diagrams illustrating three forms of the invention. v

Similar reference letters and numerals relate to similar parts.

Referring to Fig. 1, the apparatus comprises the two interrupters a a and b b, which are arranged in the consumers circuit 1 2 and adapted to make and break contact. The making and breaking of contact at a, is efiected by means of the wire 0, which is connected to the Wire 2 by means of the bar d and to the resilient contact-arm e. As long as the current in the circuit including the wire 0 does not exceed the normal value the contact-arm e is held in contact withthe contact-stud a by the said wire 0, so that current can flow freely through the circuit 1 2. a If; however, lamps f, which take more than the normal current,are inserted between the wires 1 and 2 the wire 0 will expand, owing to the heating effect of the increased current and will allow the resilient contact-arm e to move I still exceeds the limit.

the electromagnet g, the armature of which is iixed to the resilient contact-arm h. The attraction of the said armature causes contact to be temporarily broken at b. In the meantime the wire chas contracted again and contact is remade at a,so that after the breaking of contact at 1) current flows over the wire 0 and the contact a and the circuit is again broken at the latter if the current is still above the normal value. To prevent sparking at the contact I), the resistance 01 is connected in parallel thereto. Sparking at the contact a is prevented by the coil of the magnet g, which is in parallel with the said contact. To prevent interference with the action of the apparatus by external changes of temperature, the compensating device 7c is provided. This consists of a rod of the same material as the wire 6 and connected to the pivoted arm (1 and the case of the apparatus. The lengthof this rod is is effected by external changes of temperature to approximately the same extent as that of the wire 0, so that the position of the contact-arm e is not effected by such changes of temperature.

A more simple form of the apparatus is shown in Fig. 2. In this form of the a ppara tus only one interrupter a a is used, which is I also operated by means of a resilient arm 6 and a wire 0 when the latter is heated by a current exceeding the normal limit. The action of this apparatus is similar to that of the apparatus shown in Fig. 1. The expansion of the wire 0 causes contact to be broken at a, whereupon the wire contracts and remakes contact, which is again broken if the current Sparking at the contact a is prevented by the resistance i, con

nected in parallel therewith, and a compen-.

sating rod is arranged in they same manner, as shown in Fig. 1.

Fig. 3 represents another form of the appa ratus for the same purpose, which comprises two adjustable interrupters a a and b b. The interrupter a a is adapted to be operated by means of an electromagnet 1 inserted into the main circuit 2, and the interrupter I) b is operated 'by means of an electromagnet g inserted into the auxiliary circuit 3, connected in parallel with the interrupter a a. If the current exceeds the normal limit, the accu rately-adjusted magnet 1 attracts its armature, which is fixed to the resilient contactarm 2, so that contact is broken at a. Current thereupon flows to the magnet g, which attracts its armature fixed to the resilient contact-arm 71 so that contact is broken at 6'.

This causes contact to be remade at a and the action is repeated until the current is again within the normal limit. Sparking due to extra current at the contacts a and b is prevented by the resistance 11 and the magnet-coil g, respectively.

I declare that what I claim is 1. Means for temporarily breaking an elec tric circuit when the current therein exceeds a certain limit, comprising two m;.ke-andbreak contacts inserted into the said circuit, a hot-wire cut-out adapted to break one of the said contacts when the current exceeds the limit, and an electromagnet connected in parallel with the said contact and adapted to break the other contact when the first one has been broken, said contacts being constructed and arranged to make circuit automatically after such breaking, substantially as described.

2. Means for temporarily breaking an electric circuit when the current therein exceeds a certain limit, comprising two makewndbreak contacts inserted into the said circuit, a hot-wire cut-out adapted to break one of the said contacts where the current exceeds the limit, an electromagnet connected in parallel with the said contact and adapted to break the other contact when the first one has been broken, and means for compensating for external changes of temperature consisting of a rod of the same material and approximately the same length as the wire of the hot-wire cut-out and parallel to the latter, substantially as described.

3. The combination with a circuit making and breaking device for an electric circuit, said device being ada ted to automatically close after it has been been opened, of a wire controlling the opening and closing of said device, and carrying current proportional to the current flowing in said circuit, said wire being so related to said device that the ex-' pansion of the wire, when the current flowing in said circuit exceeds a certain value, operates to break said circuit and also the circuit through said wire and to maintain the circuit through said wire open while said device is open, and means for compensating for external changes in temperature, substantially as described.

4. The combination with a circuit making and breaking device for an electric circuit, said device being adapted to automatically close after it has been opened, of a wire controlling the opening and closing of said device, and carrying current proportional to the current flowing in said circuit, said wire being so related to said device that the expansion of the wire, when the current flowing in said circuit exceeds a certain value, operates to break said circuit and also the circuit through said wire and to maintain the circuit through said wire open while said device is open, and means for compensating for external changes in temperature, consisting of a rod having the same coefficient of expansion and approximately the same length as said wire and arallel to the latter, substantially as descri ed.

5. The combination with a translating de vice, of two contact making and breaking devices, said devices being adapted to close a circuit through said translating device, both of said devices bein normally closed and I In testimony whereof I have signed my each being adapted 0 automatically close l name to this specification in the presence of after being opened, means for opening one of 1 two subscribing Witnesses.

said devices upon the passage of a current in FRIEDRICH WTLHELM SCHNEIDER. excess of a certain value and means for open- Witnesses: ing the other of said devices upon the open- ERWIN DIPPEL,

ing-of the first, substantially as described. 7 MICHAEL VoLKE. 

